Detention sash assembly



Feb. 20, 1934. w. D. BAYLEY DETENTION SASH ASSEMBLY Filed Jan. 22, 1932 2 Sheets-Sheet 1 Feb. 20, 1934. w [1 EY DETENTION SASH ASSEMBLY Filed Jan. 22, 1952 2 Sheets-Sheet 2 Patented F eh. I 20, 1934 {PATENT OFFICE UNITED STATES 40 Claims.

This invention relates to sash assemblies for detention windows and in more particular to the arrangement of ventilating spaces therein and the mounting of the screens therefor.

In the construction of windows in penal institutions, asylum and the like, it has been customary to provide bars independent of the windows for preventing the escape of the inmates. The bars across the windows are expensive, distract from the appearance .of the building from the outside and has a tendency to develop undesirable complexes in some of the inmates. Where barred windows are used, the opening and closing of the windows and the screens for the windows may be provided much the same as in any other building.

In present day constructions, bars independent of the window sash assembly have been eliminated in that transversely arranged metallic muntin bars usually found in the sash assembly serve a dual purpose: namely of detention bars and the frame work of the sash assembly. This construction however, leads to difficulties when it is necessary to provide ventilating areas. In the common steel frame sash assembly as used in household, factory and other constructions, a portion of the sash assembly may be hingedly mounted or pivotally mounted so as to provide ventilating areas closed by means of a swinging sash. When the muntin bars are used as detention bars for retaining the inmates the bars are spaced quite closely both horizontally and transversely so that each space bounded by the ba-rs is quite small and one individual space does not provide sumcient ventilating area. For this reason it is necessary to use a group of spaces as ventilating area, the muntin bars extending through the spaces so that the closure for the ventilating area must either fit into each of the spaces or be independent of the spaces and fit over the outside or inside the roof as the case may be.

An object of this invention is to provide a closure fitting over a plurality of open spaces. This has been accomplished by providing a closure pivotally supported adjacent to the ventilating area.

Another object of this invention is to provide screens for the ventilating area so as to screen the area. This has been accomplished by providing an individual screen for each of the open spaces.

Another object of this invention is to provide a screen that cannot be moved. This has been accomplished by providing a screen that has a frame that snaps into position in such a fashion that this screen cannot be removed without mutilating its frame structure.

Another object of this invention is to provide a support for the movable closure engaging one 50 or more of the open ventilating spaces and to provide screens for the open ventilating spaces having the support. This has been accomplished by providing a recess or beveled edge in the frame structure of the screen so as to accome5 modate the support. The screen structure when snapped in position, being flxedly'attached so that the screen cannot be removed without mutilating its frame.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred embodiment of one form of the present invention is clearly shown.

In the drawings Fig. 1 is a front elevation of the sash mounted in the wall.

Fig. 2 is a sectional view taken substantially on the line 22 of Fig. 1. Fig. 2 being drawn to a larger scale than Fig. 1.

Fig. 3 is an enlarged fragmentary perspective view showing one of the open spaces.

Fig. 4 is a sectional view taken substantially on the line 4-4 of Fig. 1. Fig. 4' is drawn to a larger scale than the other figures.

Fig. 5 is an enlarged perspective view of the screen assembly.

Fig. 6 is an enlarged sectional view taken on the line 6-6 of Fig. 1.

Figs. 7 and 8 show modifications of sash assemblies.

In the drawings the reference character 10 indicates the sash assembly mounted in the wall 12. The sash includes the vertical muntin bars 14 and the horizontal muntin bars 16 suitably attached to the outer frame structure including the vertical frame members 18 and 20 and the horizontal frame members 22 and 24 respectively. The frame members 18,20, 22 and 24 may be suitably attached to the wall 12 inany well known manner. The transversely arranged muntin bars 14 and 16 form rectangular spaces 26 some of which are provided with window panes 28 held in position by the flanges 30 and binding material 32 such as putty, or the like abutting shoulders 31, as best seen in Figs. 2 and 4.

A group of spaces have not been provided with individual window panes as these are left open so as to form a ventilating area. The muntin bars 14 and 16 extend through the entire ventilating area and bound each of the individual spaces 40. It is quite necessary when external detention bars are 'not used to have the muntin bars extend through the ventilating area so as to prevent escape of the inmates. If desired the muntin bars passing through the ventilating area' may be offset, with respect to the bars on the outside of this area. This may be desirable so as to get away from the bar' effect. g

In many climates it is necessary to provide means for closingthe ventilating area especially in inclement weather. Instead of providing a closure for each individual space 40, a closure is used to close the entire ventilating area. This closure 41 includes the frame members 42 having the flanges 44 the upper and side frame members being identical in shape. A lower frame member 46 as viewed in Fig; 2 includes the flange 48 that cooperates with the flanges 44 in holding the window pane 50 that is sealed in position with putty 52. The lower frame member 46 also includes a downwardly extending hinge portion 54 as viewed in Fig. 2 pivotally mounted on the pintle 56 supported on a fixed hinge member 58 riveted or otherwise attached to the supporting brackets 60 having a flange or hook 62 hooking over the flange 64 of the muntin bar 16. The bracket 60 includes a flange 70 and fixedly carries a sill '12 that cooperates with members 54 and 46, respectively to form a pair of tight joints so as. to prevent drafts. The pocket 74 bounded by members 46, 54, 60 and 72 forms a dead air chamber when the closure 41 is in the closed position as best seen in Fig. 2.

Likewise a pocket is found near the upper edge of the closure 41. The pocket 80 is bounded by the flanges 30 of the' muntin bar 16 member 84 fixedly attached thereto and member 42 carrying 'a member 86. The dead air pockets 74 and 80 tend to prevent the free circulation of the air through the cracks and to form insulat-' ing spaces thereby reducing the amount of heat lost through the closure. -The sides of the closure may be provided with similar dead air pockets 80 as best seen in Fig.6.

In order to prevent insects, foreign objects, and the like from flying through the ventilating area when the closure 41 is in the open Y position and in order-to prevent the inmates from severing the muntin bars 14 and 16 so as to effect an escape there through, screens are used in each of the openings 40.

The screen assembly 100 includes a rectangular metallic frame 102 upon which the wire cloth 104 is attached as for example by solder. The frame 102 is preferably made from a strip of sheet metal having the inwardly turned flanges 106 which forms the support for the wire cloth 104. The strip 102 is preferably severed part ways in each of the corners 108, 110, and 112. Where the ends of the strip 102 come together at 114 the ends may be joined by riveting, soldering, spot welding, or in any other suitable manner. The incisions 108, 110, and 112 and the gap 116 permits the outer edges 120, 122 and 124 and 126 to be flared outwardly away from the screen frame so thatas the screen is inserted in position, usually from the outside, as disclosed in Figs. 2 and 4 the flared edges 120, 122, 124, and 126 engage shoulders 130 integral with the muntin bars 14 and 16.

The screen assembly 100 seated in the channci 132; the screen and its support 106 abutting the flange 82 and the flange 134 of the muntin bars 16 as disclosed in Fig. 2 and the flared edges engaging the shouldersv 130. From this construction it may readily be seen that the removal of the screen assembly is practically impossible without having either a special tool therefor ormutilating the flared edges, 120, 122, 124 and 126, and/or mutilating the screen cloth. In case the inmate attempts an escape and does remove the ,screen so as to sever the muntin bars 14 and 16, the screencannot be removed and replaced time after time during the process of a little sawing today, probably a little more nextweek, and so on, without showing a damaged mesh cloth and/or frame, a telltale to the guard as he inspects the premises or as he passes.

As may best be seen in Fig. 4, the individual screens fitting the openings 40 that are bounded by the brackets 60 will not accommodate the screen disclosed in Fig. 5. For this reason the structure of the screen 150 used in the openings having the brackets 60 differs from the other screens in that the end frame member 152 is provided with a slanting or beveled portion 154 that leaves suflicient space for the bracket 60. The edge 156 of the end frame 152 is seated against the shoulder 130 as in the other modifications.

In the preferred modification as disclosed in the foregoing description the muntin bars are T-shaped and the screens snapped into position, usually from the outside. It can readily be seen that any other suitable shaped muntin bar may be used. Furthermore some of the muntin bars may diifer in shape from the others as for example the'vertical bars may differ in shape from the horizontal or the bars extend- 1;;

ing across the ventilating area may differ in shape from the bars found in the glazed portion. In Fig. 7 aJT-shaped bar 160 provided with an aperture 166 receives a tongue 168 struck out of a metallic screen frame 170. modification the screen 164 cannot very well be removed without mutilating the tongue 168. In this modification the screen frame 170 has a flange 1'72 that extends flush with the inner face 174 of the flange 175 of the bar 160 so that the screen 164 extends in a plane parallel to the inner face 174, thereby preventing the severance of the flange from the inside without removal of the screen. In this modification it is necessary to remove the screen assembly before the sawing of the bars can be started.

In Fig. 8 another modification has been disclosed where rectangular bars 180 have been used as muntin bars. In this case the screen 164 is made substantially identical to the screen disclosed in Fig. 7, and the tongues 168 are seated in the recesses 182, only one of which has been shown located-in the muntin bars 180. The tongues limit the movement of the screen in one direction and a suitable stop 184 attached to the muntin bar limit the movement of the screen in the opposite direction. The stop may be mounted on either the outside or the inside,

In this frame or screen per se may be welded or soldered to the muntin bars so that the removal and replacement of the screen may easily be detected by the defacement of the screen or its frame, or both.

Although in the preferred modification the muntin bars across the glazed portion and across the unglazed portion enclose rectangular spaces, any other shape of spaces may be enclosed, as for example diamond shaped spaces formed by muntin bars running diagonally. In some installations, as for example, hospitals, insane asylums and the like, it may be desirable to have the open spaces somewhat larger than in penal institutions. These openings may be large enough to permit a person to pass therethrough if not screened. If the spaces are closed by detention screens as above described, said screens will delay or prevent ingress or egress through the area closed by the individual screens.

While the form of embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1.. In a detention window sash, a plurality of transversely arranged muntin bars forming open spaces for ventilation, individual screens for screening each of the open spaces and resilient frames for said screens interengaging with the muntin bars to retain the screens in registry with the open spac'es by the resiliency of said frames.

2. In a detention window sash, a plurality of transversely arranged muntin bars, dividing the sash into multiple spaces, window panes closing certain of the spaces leaving a group of spaces open for ventilation, each of the muntin bars bounding the open spaces having a flange near one edge and a shoulder near the other edge so as to form a channel intermediate the shoulder and the flange and a screen for closing each of the open spaces, said screen having a frame structure including one edge resiliently biased outwardly, said screen being located in said channel so that the resiliently biased edge engages the shoulder of the channel so as to prevent its removal without mutilating the edge.

3. In a detention window sash, a plurality of transversely arranged muntin bars forming a plurality of open spaces for ventilation, individual screens for screening each of said spaces and a movable closure including a frame and a window pane in said frame for stopping the circulation through said open spaces.

4. In a detention window sash, a plurality of transversely arranged muntin bars dividing the sash into multiple spaces, window panes closing certain of the spaces, leaving at least one space open for ventilation, the muntin bars bounding the space forming said open space having a flange near the outside edge and a shoulder near the inner edge so as to form a channel intermediate the shoulder and the flange and a screen for closing said open space, said screen having a frame structure including one side that has a flange resiliently biased outwardly, said screen structure being located in said channel so that the resiliently biased side engages the shoulder of the channel so as to prevent removal of the screen without distorting said resiliently biased flange.

5. In a detention window, a plurality of muntin bars forming a plurality of open spaces for ventilation, individual screens for screening each of said spaces, and a hinged closure for closing said open spaces so as to prevent circulation through said ventilation spaces.

6. In a detention window sash, a plurality of transversely arranged muntin bars forming a plurality of spaces, window panes in certainof said spaces leaving a group of open spaces for ventilation, individual screens for each of the open spaces so as to screen the ventilating area, and a movable closure for closing the screened spaces.

7. In a detention'window sash, a plurality of transversely arranged muntin bars forming a plurality of spaces, window panes in certain of said spaces leaving a group of spaces open for ventilation, individual screens for each of the open spaces, and a hinged closure for closing said open spaces to prevent circulation of air through said open spaces.

8. In a detention window sash, a plurality of transversely arranged muntin bars forming a plurality of spaces, window panes in certain spaces leaving a group of spaces open for ventilation, individual screens for each of the open spaces and a movable closure closing the screened spaces so as to prevent the flow of air through the ventilating area, said closure including a frame having an open space and a window pane seated in said frame.

9. In a detention sash, a plurality of transversely arranged muntin bars forming at least one open space, each of said bars including a web, a flange near one edge of the web, and a shoulder near the other edge, said flange, web and shoulder forming a channel, a screen for screening said open space, said screen including a frame fitting said open space, said frame having a sheet metal flange on one side disposed normal to the plane of said screen, said sheet metal flange being provided with an outwardly flared edge so that as the screen is inserted in the open space, the outwardly flared edge snaps into the channel so as to engage the shoulder thereby preventing the removal of the screen.

10. In a detention sash, a sash frame having a screen receiving seat, said frame forming an open space for ventilation and including a muntin bar adjacent to said open space, said bar having a web, a shoulder near one edge of the web, a flange near the other edge, said web, shoulder and flange forming a channel, a screen assembly including a frame fitting said screen receiving seat, said frame including a sheet metal flange disposed substantially normal to the plane of the screen assembly, said flange including an outwardly flared edge so that as the screen is inserted in said frame, the flared edge snaps into said channel so as to engage said shoulder thereby preventing the removal of the screen.

11. In a detention sash having an open space for ventilation, a frame, said frame including a pair of parallel muntin bars arranged on opposite sides of said ventilation space, each of said bars including a web, a flange near one edge of said web, a shoulder near the other edge of the web, said web, shoulder and flange forming a channel, a screen assembly for screening said ventilation space, said screen assembly including a frame, said frame having a pair of parallel sheet metal flanges extending normal to the plane of the screen assembly, each of said flanges having an outwardly flared edge so that as'the screen is inserted into the ventilating space, the flared edges snap into said channel so as to engage said shoulders thereby preventing the removal of the screen assembly.

12. In a detention sash, a frame having an open space for ventilation, a screen assembly for screening said ventilation space, said frame having a seat facing said ventilation space for receiving the screen assembly, said seat including a channel having a shoulder, the screen assembly including a frame having flanges disposed normal to the plane of said screen, said flanges having outwardly flared edges so that as the screen assembly is inserted in the screen receiving seat the flared edges snap into said channel and engage said shoulder so as to prevent the removal of the screen.

13. In a detention sash, a plurality of transversely arranged muntin bars dividing the sash into multiple spaces, window panes closing certain of said spaces, leaving at least one of the spaces open for ventilation, said muntin bars bounding the space for ventilation having a flange near one side and a shoulder near the other so as to form a channel intermediate the shoulder and the flange and a screen assembly for closing said area, said screen assembly having a frame structure including flanges around the outer periphery of the screen, said flanges being arranged normal to the plane of the screen, each of the flanges having a flared edge extending outwardly so that as the screen is inserted in the open space, said outwardly flared edges snap into said channel so as to prevent the removal of the screen from said open space.

14. In a detention window sash, a plurality of transversely arranged muntin bars dividing the sash into multiple spaces, window panes closing certain of the spaces leaving at least one of the spaces open for ventilation, a screen assembly for screening said open space, the muntin bars bounding the open space having a stop for limiting the movement of the screen in one direction and screen stopping abutments, said screen frame assembly including a frame for supporting the wire mesh cloth, said frame including peripheral flanges extending normal to the plane of the screen, said flanges having an outwardly flared edge for engaging said stop abutments so that as the screen assembly is snapped into position its removal is prevented unless the flared edges are distorted.

15. In a detention window sash, a plurality of transversely arranged muntin bars dividing the sash into multiple spaces, window panes closing certain of the spaces, leaving a group of spaces open for ventilation, a screen assembly for screening said open spaces, the muntin bars bounding the open spaces having each a stop for limiting the movement of the screen in one direction and screen stopping abutments for holding the screen in position, said screen assembly including a frame having peripheral flanges flared outwardly for engaging said stop abutments so that as the screen is snapped into position, the removal of the screen is prevented without distorting the flared flanges.

16. In a detention window sash, a plurality of transversely arranged muntin bars dividing the sash into multiple spaces, window panes closing certain of the spaces, leaving a group of spaces open for ventilation, the muntin bars bounding the open spaces having a flange extending into the open space, a shoulder disposed from the flange, said flange and shoulder forming a channel, and an individual screen assembly for screening each of said open spaces, said screen assembly including a frame structure having outwardly flared flanges along the periphery of the frame so that as the screen assembly is inserted in the open space the outwardly flared flanges snap into-the said channel'so as to prevent the removal of the screen from the said open spaces.

17. In a detention window sash, a plurality of transversely arranged muntin bars dividing the sash into multiplespaces, window panes closing certain of the spaces leaving at least one space open for ventilation, the muntin bars bounding the open space having a flange extending into the open space and a shoulder disposed from the flange, said flange and shoulder forming a channel, a movably mounted closure arranged to close said open spaces thereby preventing ventilation through the open space, a support for said closure, said support including hooks extending over the flange of one of said muntin bars boundingsaid open space, and a screen assembly for screening said open space, said screen assembly including a frame structure having outwardly flared flanges along the periphery of the frame, the flange along one side being beveled so as to leave space for said hook, the outwarly flared flanges snapping into said channel as the screen is inserted into the open space so as to prevent the removal of the screen from said open space without deforming the flared edges.

18. In a detention window sash, a plurality of transversely arranged muntin bars dividing the sash into multiple spaces, window panes closing certain of the spaces leaving a group of spaces open for ventilation, individual screen assemblies for screening each of said open spaces, the muntin bars bounding the open spaces having a flange extending into the open space and a shoulder disposed from the flange, said flange and shoulder forming a channel for receiving the screen assembly, a movably mounted closure arranged to close said open spaces, a support for said closure, said support including a member hooked over the flange of one of said muntin bars bounding at least one of said open spaces, the screen assembly closing said one open space including a frame structure having outwardly flared flanges along the periphery thereof the flange along one side being beveled so as to leave space for the hook closure support, the outwardly flared flanges snapping into said channels as the screen is inserted in the open space so as to prevent the removal of the screen from said open space without deforming the flared edges.

19. In a detention window sash, a plurality of transversely arranged muntin bars dividing the sash into multiple spaces, window panes closing certain of the spaces leaving a group of spaces open for ventilation, a screen assembly for screening said open spaces, the muntin bars bounding the open spaces having flanges extending into said open spaces and shoulders disposed from the flanges, a flange and a shoulder on a muntin bar forming a channel for re- 1 ceivingthe screen assembly, said screen assembly including a frame structure having outwardly flared edges along the periphery of the frame so that as the screen assembly is snapped into position the flared edges engage the shoulder so as to prevent the removal of the screen without distorting the flared edge, and a closure for said group of open spaces, a support for said closure, said closure being pivotally mounted on the support so that as the closure is moved into parallel relation with respect to vthe plane of the said'open spaces the ventilation is shut off.

20. A detention window including transversely disposed muntinbars dividing the window into multiple small spaces and duofunctionally serving to support window panes and also serving as jail bars, window panes closing a portion of the spaces leaving a group of such spaces open for ventilating purposes, a relatively adjustable closure common to the group of open ventilating spaces, and individual screens for each of the ventilating spaces separately supported by said muntin bars in registry therewith.

2,1. A detention window including glazed and unglazed portions and having a plurality of muntins dividing the glazed and unglazed portions into multiple spaces, certain of the muntins extending over the unglazed portions to act as detention bars, a closure adjustably disposed adjacent the unglazed portion and adapted to close such spaces, and individual screen sections for the several unglazed spaces fixedly mounted in overlying relation thereto.

22. The combination with a window structure including transversely disposed muntin bars dividing the window structure into multiple spaces of separate window screen units insertable in certain of said spaces each comprising a panlike structure having a foraminous bottom and perpendicular resilient marginal walls, said walls being outwardly flared and split at their corners to facilitate independent spring adjustment thereof into engagement with the muntin bars.

23. The combination with a supporting structure including transversely disposedmuntin bars dividing the structure into multiple spaces, and window screen units engageable in certain of said spaces each comprising a section of wire mesh fabric and a marginal frame of spring material projecting in perpendicular relation to the plane of the screen fabric for yielding tensioned engagement with the muntin bars of the supporting structure.

24. A detention window including a plurality of intersecting muntins dividing the window into multiple small spaces, some of which are glazed and others of which are left unglazed for ventilating purposes, said muntins being flanged at their inner sides, an adjustable closure common to the unglazed spaces, and a support for the closure including a bar having a marginal flange extending into down-turned overlapping relation with the flange of the muntin bar.

25. A detention window of the character de-.

scribed having glazed and unglazed portions, including muntin bars extending across both the glazed and unglazed portions, said muntin bars being of substantially T-shaped in cross section, the medial flange of such T-shaped muntins be,- ing marginally enlarged to form an offset in spaced relation with the transverse flange of the bar and adapted to form an interlocking abutment for a screen unit and a resilient screen unit yieldingly engageable behind the offset of said bar.

26. A muntin bar for a detention window of the character described of substantially ginal expansible screen unit engageable with the muntin bar by being expanded behind said shoulder.

2'7. A muntin bar for a detention window of the spring frame having interlocking engagementwithin said channel.

28. In a detention window, glazed and unglazed portions, intersecting muntins dividing the glazed and unglazed portions into multiple spaces and including a flanged bar defining a boundary of the unglazed portion, an adjustable closure for the unglazed portion and a flanged bar cooperating with the closure, the flange of which overhangs in reverse relation the flange of the first mentioned flanged bar.

29. In a detention window, glazed and unglazed portions, intersecting muntins dividing the glazed and unglazed portions into multiple spaces and including a bar defining a boundary of the unglazed area, an adjustable closure for the unglazed area, a bar cooperating with the closure, said bars having overlapping interlocking engagement one with the other.

30. In a detention window, glazed and .unglazed portions, intersecting muntins dividing the glazed and unglazed portions into multiple spaces and including a bar defining a boundary of the unglazed portion, an adjustable closure for the unglazed portion, and a sill for the closure extending within certain spaces of the unglazed portion in overhanging relation with the boundary bar thereof.

31. A detention window having glazed and un glazed portions, muntin bars extending across the glazed and unglazed portions, an adjustable closure for the unglazed portion, a bar cooperating with the closure-having its opposite margins flanged in opposite directions and arranged with its outer flanged margin extended in overhanging relation toward a muntin bar defining a boundary of the unglazed portion and with its inner flange margin extended in overhanging relation with the unglazed portion.

32. A detention window having glazed and unglazed portiens, muntin bars extending across the glazed and unglazed portions, an adjustable closure for the unglazed portion, including an angle bar frame therefor having its angle exteriorly disposed, a sill to which the closure is hinged, said sill including a bar disposed in marginally overhanging relation with a muntin bar 'deflning a boundaryof the unglazed portion, and an upstanding flange carried by the bar upon which one flange of the angle bar frame of the closure abuts when closed, the other flange of the angle bar frame of the closure being hinged to the inner margin of said sill bar, whereby when closed said sill bar and flange and the angle bar frame of the closure enclose an intermediate space.

33. A detention window including transversely disposed muntin bars dividing the window into multiple small spaces and duo-functionally to support the window panes and also serving as jail bars, window panes closing a portion of the spaces leaving a group of such spaces open for ventilating purposes and individual screens for each of the ventilating spaces separately supported by said muntin bars and registering therewith, said screen including a member extending along the periphery that is distorted when the screen is inserted.

34. A detention window including transversely disposed muntin bars dividing the window into multiple small spaces and duo-functionally to support the window panes and also serving as jail bars, window panes closing a portion of the spaces leaving a group of such spaces open for vfor said portion and a closure cooperating therewith.

36. In a detention window, glazed and unglazed portions, intersecting muntins dividing the glazed and unglazed portions into multiple spaces, and including a flanged bar defining a boundary of the unglazed portion and an extension carried thereby projecting beyond the plane of the muntins to receive a closure for such unglazed portion, said extension including flanges extending inwardly toward the ventilating area and a closure member cooperating therewith.

37. A detention window including glazed and unglazed portions and having a plurality of muntins dividing the glazed and unglazed portions into multiple spaces, certain of the muntins extending across the unglazed portions to act as detention bars and adapted to close such spaces, and individual tell-tale mesh workv secshaped cross sectional form, the medial flange tions for the several unglazed spaces fixedly mounted in overlying relation thereto, the inner side of the mesh work section being arranged in a plane coincident with the inner faces of the muntin bars so as to be mutilated when an attempt is made to cut the muntins thereby serving as a tell-tale.

38. A muntin bar fora detention window of the character described of substantially T- of which is longitudinally grooved in the side thereof forming a shallow channel intermediate the transverse flange of the bar and the margin of the medial flange, and a metal mesh-work unit including a frame having locking engagement with said channel.

39. In a detention window, glazed and unglazed portions, intersecting muntins dividing the glazed and unglazed portions into multiple spaces, and including a flanged bar defining a 98 boundary of the unglazed portion, an extension carried thereby projecting beyond the plane of the muntins to receive a closure for such unglazed portion and a closure member cooperating therewith and a mesh work assembly asso- 100 ciated with the unglazed portion for preventing sawing of the bars. I

40. A detention window of the character described having glazed and unglazed portions, T-shaped muntins bars extending across both'105 glazed and unglazed portions and individual telltale mesh work sections for the several unglazed spaces fixedly carried by said T-shaped bars, said mesh work sections including a frame portion extending flush with the irmer face of the T-bar, said frame portion carrying the screen in a plane substantially coincident with the inside of the window so as to be mutillated when an attempt to saw the muntins is made, thereby serving as telltales.

' WILLIAM D. BA'YLEY. 

